login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A054007 Numbers k such that k and k+1 have the same sum but an unequal number of divisors. 4
206, 957, 1364, 2974, 4364, 14841, 18873, 19358, 20145, 24957, 36566, 56564, 74918, 79826, 79833, 92685, 111506, 116937, 138237, 147454, 161001, 162602, 174717, 190773, 193893, 201597, 230390, 274533, 347738, 416577, 422073, 430137 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..8304 (terms below 10^13, calculated from the b-file at A002961)

FORMULA

Members of A002961 which are not members of A054004

MATHEMATICA

Select[Range[100000], DivisorSigma[0, #] != DivisorSigma[0, # + 1] && DivisorSigma[1, #] == DivisorSigma[1, # + 1] &] (* Jayanta Basu, Mar 20 2013 *)

CROSSREFS

Cf. A000005, A000203, A002961, A005237, A053249, A054004, A054005, A054006.

Sequence in context: A113934 A260101 A113490 * A285754 A201032 A133149

Adjacent sequences:  A054004 A054005 A054006 * A054008 A054009 A054010

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu) Jan 12, 2000

EXTENSIONS

More terms from Jud McCranie, Oct 15 2000

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 16 08:15 EDT 2019. Contains 328051 sequences. (Running on oeis4.)